The Dominantly Inherited Alzheimer Network (DIAN), Core B: Clinical is responsible for the protocol implementation of all clinical operations for the research studies, including participant recruitment and retention, and protection; performing clinical evaluations including CDR and psychometric testing, completing imaging, blood and CSF collections, and offering genetic counseling and testing. The study of longitudinal progression of dominantly inherited Alzheimer disease will likely lead to a better understanding of the causes of Alzheimer disease. DIAN studies inform about potential methods of detecting AD and the sequence of events at the earliest stages of the illness, even before clinical symptoms have begun. The DIAN-Observational study will continue to support and enable preventative treatments to be tested. The Clinical Core will obtain highly sensitive clinical evaluations and psychometric testing to determine the earliest symptoms and progression rates. Novel computerized validated cognitive tests will be added to the cognitive battery. The longitudinal study of cognitive and clinical measures will be analyzed by estimated years to symptomatic onset and followed longitudinally to estimate progression and rates of change. The Clinical Core also will monitor and oversee imaging studies, blood and CSF to measure biomarker changes which may occur before symptoms. The data generated from these studies will be used by DIAN investigators to advance the understanding of the causes of Alzheimer disease, methods of early detection, and support ongoing and future preventative treatments.